Motorized vehicles generally include a drive transmission with many multi-part assemblies for delivering driving power from an engine to two or more wheels. For example, a drive transmission for the rear wheels of a motorized vehicle may include a final drive unit including a differential at a rear axle and a pinion assembly connecting the differential to a primary drive shaft. The pinion assembly may be coupled to the drive shaft with a universal joint or U-joint that enables the drive shaft to pivot with respect to the pinion assembly during operation of the motorized vehicle. As well understood in the automotive field, these universal joints are typically formed between two yokes located on the pinion assembly and the drive shaft. Thus, the pinion assembly includes a splined pinion shaft configured to receive a yoke. The yoke is slid onto the pinion shaft and locked in position by a pinion fastener or pinion nut coupled to a threaded free end of the pinion shaft. Alternatively, the pinion assembly may be coupled to the drive shaft with a flange member that includes internal splines for engaging the splined pinion shaft.
In some circumstances the pinion assembly must be disassembled to repair or replace the components of the pinion assembly or the other elements of the drive transmission (such as the differential). Conventionally, this disassembly of the pinion assembly requires two distinct tools for various steps in the disassembly process. First, a plate-shaped yoke holding fixture must be bolted onto the yoke or flange member so that a breaker bar may hold the yoke or flange member in position during removal of the pinion fastener with a standard socket wrench. Second, a yoke removal tool is coupled to the yoke or flange member, the yoke removal tool including a cross-bar with a central threaded aperture and a bolt engaged with the aperture. As the bolt is rotated to advance through the aperture in the plate, the cross-bar pulls the yoke or flange member outwardly and off the splines of the pinion shaft. Consequently, two separate tools are required every time the yoke or flange member is to be removed from the pinion shaft, and the pinion disassembly process is slow and inefficient.
Thus, it is an object of the invention to provide an improved pinion disassembly tool and method.